Acute kidney injury (AKI) is common after cardiac surgery and impacts short and long-term mortality. The parent grant, RO1 (HL-085757), focused on developing novel tools for assessment of structural kidney damage and comparing new tests to the traditional measurement of serum creatinine, which is a measure of kidney filtration. We created the Translational Research Investigating Biomarker Endpoints (TRIBE) consortium and fulfilled the goals of all of the specific aims of the grant and reported results on several novel urine and plasma biomarkers of kidney injury, such as urine IL-18, urine and plasma NGAL, urine albumin, plasma BNP, and plasma cystatin C. We prospectively enrolled over 2000 adults and children undergoing cardiac surgery at 9 centers and developed a robust sample biorepository linked to clinical variables. In this competitive renewal, we will enrich our cohort y gathering information on long-term outcomes in adult and pediatric patients through continued phone calls, in-person visits, and linkages of the TRIBE cohort to national administrative databases. We will also perform measures of three promising urine biomarkers (KIM- 1, L-FABP and urine cystatin C) and two plasma biomarkers (CK-MB, high sensitivity troponin-T) on the samples stored in our biorepository. With a total of 11 measured biomarkers (from the parent and renewal grants), we will create multi-marker panels for predicting AKI and other outcomes using emerging and innovative statistical methods. We hypothesize that the pre-operative and post-operative biomarkers will not only predict AKI, but also will predict longer-term complications years later, such as chronic kidney disease, end-stage renal disease, and death. Additionally, we hypothesize those patients with high biomarker levels, but no evidence of clinical AKI (subclinical AKI); will also have poor long-term outcomes. The availability of reliabl clinical models for these short and long-term outcomes will assist with informed decision making, adequate planning for surgeons, post-discharge management, and inform future clinical trials. Our primary research aims are: Aim 1: To ascertain long-term outcomes associated with AKI after cardiac surgery in adults and children. Aim 2: To construct a multi-marker biomarker panel to improve risk prediction of outcomes in adults and children.